package com.hmdp.utils;

import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
public class RedisIdWorker {
    private static  final long BEGIN_TIMESTAMP=1704067200L;
    private static  final int COUNT_BITS=32;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    public  long nextId (String keyPrefix){
        //1.生成时间戳
        LocalDateTime now=LocalDateTime.now();
        long nowsecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp=nowsecond-BEGIN_TIMESTAMP;
        //2.生成序列号
        //2.1获取当前日期,精确到天
        String date=now.format(DateTimeFormatter.ofPattern("yyy:MM:dd"));
        //2.2自增长
        long count= stringRedisTemplate.opsForValue().increment("icr"+keyPrefix+date);

        //3.拼接返回,位运算,把时间戳左移32位,再与count做位运算
        return  timestamp<<COUNT_BITS | count;

    }

}
